Official Freewing 90mm F-4 Phantom II Thread

[locharrow]

Being a kick in the :warning: off an octogenarian I don't really throw my planes around the way I used to but today I got a bit inspired and let loose (for me) ! After a few low passes just to admire the beast I climbed out levelling off into a hard left bank turn. The nose started to drop so I thought feed in some rudder to keep it up. Well!!! The nose leaped up and the plane went into a hard right nose down turn before I had time to blink. I was high and not in any trouble but my word I've never seen a reaction like that to a squeeze on the rudder . Never put any expo on the rudder but I will now !!

[Alphonso]

Being a kick in the :warning: off an octogenarian I don't really throw my planes around the way I used to but today I got a bit inspired and let loose (for me) ! After a few low passes just to admire the beast I climbed out levelling off into a hard left bank turn. The nose started to drop so I thought feed in some rudder to keep it up. Well!!! The nose leaped up and the plane went into a hard right nose down turn before I had time to blink. I was high and not in any trouble but my word I've never seen a reaction like that to a squeeze on the rudder . Never put any expo on the rudder but I will now !!

Hi there, may I ask where your CG is in relation to the manuals CG point. The reason I ask is that it's more usual to feed a little rudder into the turn to maintain a constant height with this one. Particularly with stock CG. Ihaven't flown with a CG forward of 190 as too much elevator is needed and it climbs too noticeably at speed. An early review by Ryan stated a nasty tendency when overly nose heavier. Seeing as you dropped the nose in a hard bank on a model that naturally climbs at speed and additionally with high power due to its thrust line, makes me suspect you're quite nose heavy and carrying excessive elevator. As you banked, you may have stalled at speed as the plane rotated into the turn. Something is not ideal with your balanec, my rudder is mechanically maxed out with no expo.and I'm no aerobat.rudder turns are quite soft with little roll coupling, I always start a scale, level turn with a brush of rudder to keep it looking controlled.
I have stalled more than once with this when holding too much elevator in a slow turn, got complacent after flying the F22 with the nose up. It recovers quickly but reminds you to respect the elevator.
Good luck with your findings and do double check your CG,

Regards,Allan

[locharrow]

"Hi there, may I ask where your CG is in relation to the manuals CG point."

I've been at 185 and getting little change to level flight while transitioning from mid to full throttle. There is also very little change when using mid or full flaps so I am not keen on moving the CG . I realise that it would make the plane "livelier" but, as I said, I don't throw them round as I used to do. However, I may be an old dog but I'm certainly able learn new tricks so next flight, when this @#@### rain stops I will shift the battery back 5mm and take off 2% up trim and give it a try. If I wet my breeks I will expect compensation !! :stuck_out_tongue_wi

[Hugh Wiedman]

"Hi there, may I ask where your CG is in relation to the manuals CG point."

I've been at 185 and getting little change to level flight while transitioning from mid to full throttle. There is also very little change when using mid or full flaps so I am not keen on moving the CG . I realise that it would make the plane "livelier" but, as I said, I don't throw them round as I used to do. However, I may be an old dog but I'm certainly able learn new tricks so next flight, when this @#@### rain stops I will shift the battery back 5mm and take off 2% up trim and give it a try. If I wet my breeks I will expect compensation !! :stuck_out_tongue_wi

I've been flying both my F-4's for the last 50 or so flights at around 195 mm (believe the manual is at 190 mm, correct?). I'm using a RT 6250 35C battery and get at least 4 minutes of relatively aggressive flying on it. For me, it seems to fly extremely well at that CG and lands very nicely, slows down and floats nicely and allows me to get it into enough of a nose up attitude to no longer bend/break the nose gear pin. I do get a big change in attitude with both take-off and landing flaps at that CG. Up trim of 10% on take off and 15% on landing flaps (or in TX talk, -10% & -15% in the flap system compensation). But that's just me. I felt, and this is just IMO, that at a more nose heavy configuration, the F-4 was like a "bull in a china shop". The body of the jet seemed to follow the nose where ever it was pointed (sorry, hard to describe), almost as if it was being pulled around by the very front of the jet and the rest just followed. By moving the CG back a bit, it became more responsive and seemed to "lose weight", if you know what I mean.

[Alphonso]

"Hi there, may I ask where your CG is in relation to the manuals CG point."

I've been at 185 and getting little change to level flight while transitioning from mid to full throttle. There is also very little change when using mid or full flaps so I am not keen on moving the CG . I realise that it would make the plane "livelier" but, as I said, I don't throw them round as I used to do. However, I may be an old dog but I'm certainly able learn new tricks so next flight, when this @#@### rain stops I will shift the battery back 5mm and take off 2% up trim and give it a try. If I wet my breeks I will expect compensation !! :stuck_out_tongue_wi

I can see why 185 feels comfortable with stock power for normal flight, my original 190mm on maiden felt very solid and elevator use on landing slowed her up effectively with little pitch effect. The issue for me was when I gave it some WOT, it would climb noticeably, however I'm running 10S and high voltage lipos at nearly 4KW peak which I know introduces other issues with an arguably less than optimal thrust line.
If you do try say, 190 - 195 , I can assure you it won't become a pitch sensitive, bucking bronco. Yes I have some flap / elevator mix, I initially followed the books mix but actually had to add 2mm more than the books figures. Others here and the other forum often reported similar results.
The main reason I mention CG again ( and I do so with tact and consideration after reading recent posts on other threads😁 ) is because of your need for rudder to lift the nose in a bank. This sounded unusual for this model in my limited experience. My Yak 130 does exactly what you described if I'm too aggressive with controls in a hard bank and that plane is too nose heavy as I didn't want to buy more smaller lipos it's only 70mm and I do it for fun up high 😊.

Best of luck, Allan

[Alphonso]

I've been flying both my F-4's for the last 50 or so flights at around 195 mm (believe the manual is at 190 mm, correct?). I'm using a RT 6250 35C battery and get at least 4 minutes of relatively aggressive flying on it. For me, it seems to fly extremely well at that CG and lands very nicely, slows down and floats nicely and allows me to get it into enough of a nose up attitude to no longer bend/break the nose gear pin. I do get a big change in attitude with both take-off and landing flaps at that CG. Up trim of 10% on take off and 15% on landing flaps (or in TX talk, -10% & -15% in the flap system compensation). But that's just me. I felt, and this is just IMO, that at a more nose heavy configuration, the F-4 was like a "bull in a china shop". The body of the jet seemed to follow the nose where ever it was pointed (sorry, hard to describe), almost as if it was being pulled around by the very front of the jet and the rest just followed. By moving the CG back a bit, it became more responsive and seemed to "lose weight", if you know what I mean.

I needed a lot of up to exit loops with the forward CG and yes it felt heavier. Much better now and a carbon stiffened elevator pushrod really helped as the servo has to push for up which I believe leads to more flex of the original rod.

[locharrow]

"I needed a lot of up to exit loops with the forward CG and yes it felt heavier. Much better now and a carbon stiffened elevator pushrod really helped as the servo has to push for up which I believe leads to more flex of the original rod"

Just ten minutes ago I put the carbon tube on my new f4 tail rod and locked down the servo ...this time I filled the melted holes under the servo lugs to overspill with Gorilla glue, last time I used epoxy and it never budged, even survived my tree incident !! Varnished the wings and other bits, all looking great !!

Still pouring with rain !! :sob:

[Alphonso]

I have followed the concerns regarding elevator servos coming loose and was going to make a ply tray and change to Hitec, however Icant budge my servo so shall leave that for now. No criticism of stock servo, I just like the precision and programming of Hitecs.
Hope your weather clears up, we're usually blessed with a long season down on the south coast but the last 2 Winters have been a bit soggy.

[locharrow]

We don't get much soggy...a lot of frozen !! Back in the 70's I flew a Maratuka Phantom of a frozen loch just down the road.... it is THE best runway of all, rudder spins on the ice etc, the landing roll out in reverse is something to behold !! :snowflake:

[Waconut]

Hi guys,
I have had my F-4 finished for about 5 months and I am finally getting ready to fly it. I installed a gyro at the behind the back of the battery bay and I have a Admiral 5000 installed all the way forward and I am balancing at 205mm.
I hate to add dead weight but at this point I don’t see any other options. Do you think the plane will be too tail heavy at 205mm in the balance point?
Thanks!!

[Waconut]

After not receiving any replies I bit the bullet and glued 3/4 oz lead egg sinker into the base of the nose cone. This gave me a balance point of 195mm. I can always remove it later if I feel I can move the CG back.

[T- Elbert]

Use the factory cg it works very well. I have two motion F 4’s and love them. Read up through this forum issues can pop up like elevator servo. start out with 2:30 flights and work up from there

[Waconut]

Use the factory cg it works very well. I have two motion F 4’s and love them. Read up through this forum issues can pop up like elevator servo. start out with 2:30 flights and work up from there

I already did the elevator mods.

[locharrow]

After not receiving any replies I bit the bullet and glued 3/4 oz lead egg sinker into the base of the nose cone. This gave me a balance point of 195mm. I can always remove it later if I feel I can move the CG back.

I didn't reply because I am not settled on my own CG yet but my first thoughts were as to why your at 205 because I have a heavy metal 6s Freewing fan in mine and the battery, a 5000 Turnigy H/Duty still has room to move forward a tad at 185. The other thing I would mention is that, if your weighting the nose, a bit of glue would not go amiss as the inertia of a bump on take off or landing could dislodge it. Good luck with the maiden and don't get so engrossed in admiring it that you forget your flying it !! :pray:

[Waconut]

While I had the F-4 out I decided to weather it up a bit. I think it looks better dirtied up a bit.

[Elbee]

Use the factory cg it works very well. I have two motion F 4’s and love them. Read up through this forum issues can pop up like elevator servo. start out with 2:30 flights and work up from there

TE, Great advice and Welcome to 'The Squawk", Sir. Glad to have you onboard. Best, LB

[f4u ausie]

Hey guys wanted to ask. ,,,. Once I conquer. The f35 and mig. 17 lockdown over soon!! Would a f. Wing f4 b to big a jump. On the jet journey?? Must b the f4 thing. Luv f4u and f4. Luv those droopy. elevators so wasn't sure to get f4 or. Maybe f18 thank in advance

[Evan D]

I think a F-4 would be a good step for you.

[locharrow]

I think a F-4 would be a good step for you.

No brainer........................Awesome v :poop:.................

[f4u ausie]

I'm keen on the grey. Hoot Gibson scheme. Think that's him